A host is, for example, a server, laptop, or mobile phone that communicates with another host or subscriber end station, such as another server, laptop, or mobile phone. A host that runs TCP utilizes a TCP connection to send and receive packets with another host or subscriber end station. An edge router assists the host by transmitting packets over the TCP connection to and from the host. The edge router does not terminate or initiate the TCP connection, but rather acts to ensure that packets are transmitted correctly.
Multipath Transmission Control Protocol (MPTCP) is a potential implementation that would have various benefits over TCP. MPTCP utilizes multiple paths for one TCP connection and therefore allows for higher throughput in data communications. Higher traffic applications, such as video, could be more easily supported using MPTCP. However, MPTCP is not widely implemented and even if it were implemented in this case, hosts that run TCP would not be capable of taking advantage of MPTCP if the TCPIP stack on the host is not upgraded. Upgrading the TCPIP stack on every single IP enabled host would be a challenging and time-consuming process, e.g., on the order of years or decades to update billions of such devices. Moreover, coordinating the upgrades can add to the complications of this process.